i) Field of the Invention
The present invention relates to laundry machines and/or methods of operation of laundry machines, and in particular to improvements in the admission of water thereto.
ii) Summary of the Prior Art
In a laundry machine, whether a horizontal axis or vertical axis type machine, the machine performs a series of cycles, usually beginning with a wash cycle, proceeding through one or more rinse cycles and ending with a spin cycle. In the wash cycle water is admitted to the machine, usually to a tub or other water container within which a perforated drum or bowl rotates and contains the laundry. The wash cycle may fill or partially fill a container to submerge the washing load in a deep wash, or a lesser volume of water may be admitted and this may be recirculated through the laundry load by a recirculation pump and appropriate spray nozzle. These washing methods are well known in the art for both horizontal axis and vertical axis machines.
It is recognised that the recirculation type washing method uses significantly lower volumes of water, particularly in a vertical axis machine. Furthermore it is thought that the greater detergent concentration in the wash liquid during a recirculating type wash leads to better soil removal and/or lower total detergent usage. Accordingly a relation type wash is becoming a preferred wash particularly for vertical axis machines, Horizontal axis machines, by virtue of their nature tend to already have a low water volume in the water container with the clothes being dipped through the water pool by rotation of the horizontally aligned perforated drum.
For proper detergent activation without potentially damaging clothes which are susceptible, for example, to shrinkage or dye loss, it is necessary to have accurate control of the temperature of the body of wash liquid that is in the machine. With the significantly reduced volumes in the machine this is made significantly more difficult if there are fluctuations in the temperature of the water supply.
It is therefore an object of the present invention to provide a laundry machine and/or methods for the operation of a laundry machine which go someway towards overcoming the above disadvantages or which will at least provide the public with a useful choice.
In a first aspect the invention consists in a laundry machine including a washing enclosure to which a supply of water is admitted in use, first and second valve means for connection to hot and cold water supply sources respectively, temperature sensing means which sense the temperature of either a combined water flow from the first and second valves or the water collected in the water enclosure, and a controller which, in a washing operation, executes an initial fill program comprising the steps of opening only the hot water valve and monitoring the temperature indicated by the temperature sensing means, followed by a warm fill program once the sensed temperature has reached or exceeded a threshold temperature.
In a second aspect the invention consists in a laundry machine including a washing enclosure to which a supply of water is admitted in use, first and second valve means for connection to hot and cold water supply sources respectively, temperature sensing means which sense the temperature of either a combined water flow from the first and second valves or the water collected in the water enclosure, and control means which, in a washing operation, perform the steps of opening the hot water valve and monitoring the temperature indicated by the temperature sensing means, and only opening the cold valve once the sensed temperature has reached or exceeded a threshold temperature is calculated based on the initial temperature of the supply of water flowing through said first valve.
In a third aspect the invention consists in a laundry machine including a washing enclosure to which a supply of water is admitted in use, first and second valve means for connection to hot and cold water supply sources respectively, temperature sensing means which sense the temperature of either a combined water flow from the first and second valves or the water collected in the water enclosure, and control means which, in a washing operation, perform the steps of determining a wash temperature, opening the hot water valve and monitoring the temperature indicated by the temperature sensing means, and only opening the cold valve once the sensed temperature has reached or exceeded a threshold temperature, said threshold temperature being less than said wash temperature.